Esters of chlorinated phenoxyacetic acids



Patented May 13, 1952 ESTERS F CHLORINATED PHENOXYACETIC ACIDS William W. Allen, Ambler, Pa., assignor to American Chemical Paint Company, Ambler, Pa., a corporation of Delaware N 0 Drawing. Original application September 23,

1949, Serial No. 117,501. Divided and this application April 7, 1951, Serial No. 219,889

6 Claims. (Cl. 260-473) The present invention relates to esters of chlorinated phenoxyacetic acids, and more particularly to the esteriflcation products of ZA-dichlorophenoxyacetic acid and 2.4.5-trichlorophenoxyacetic acid with the ethers of diethylene glycol.

This application is a division of application Serial No. 117,501 filed September 23, 1949.

The primary object of the invention is to Another object of considerable importance is to provide a new class of esters which can be prepared very economically or inexpensively, and which can be embodied or incorporated into emulsions, solutions, dispersions or other soluprovide a wholly new class of esters of chlorinated l0 bilized form in a relatively simple, inexpensive phenoxyacetic acids, which may be used for the manner, and when so formulated can be readily various purposes for which the acids themselves applied with conventional equipment to weeds or the conventional esters have been previously in the immediate presence of desired vegetation. used but to better advantage and without the The present invention is based in large measure shortcomings inherent in the previously used upon the discovery or observation that 2.4-D acid 2.4-1) and 2.4.5-T compounds. and 2.4.5-T acid can be readily esterified by At this point, it is to be noted that Patent No. means of the ethers of diethylene lyc and at 2,390,914, issued December 11, 1945, to the Amerithe r ltin es ers can be used for the same can Chemical Paint Company of Ambler, Pennpurposes and in S bsta tia y the same manner sylvania, as assignee of Franklin D. Jones, disas the conventional esters without, however, mancloses a Wholly new class of systemic or translost t e b o c l y, w ch has cated herbicides containing a halogenated phe- P 9 such a d v a e in the ease of said noxy monocarboxylic aliphatic acid, salt or ester D art estersthereof. The preferred halogenated products It is to he noted at s point that many Of the mentioned in the patent are the chlorinated pheethers of diethylene glycol e a ailable On the noxyacetic compounds such as 2.4-dichlorophemarket under the trade-mark the noxyacetic acid, 2.4.5-trichlorophenoxyacetic diethylehe glyeol mOnOethyl t e be g referred acid, and their conventional salts and esters. to p y as and e Others be Formulations having these compounds as their referred to as With p x such as active ingredients have become increasingly im- D DY b y y "p pol-taut in the control of weeds, and now oonsti- 813C. to indicate the nature Of the substituent which tute a very important class of selective weedhas p ed the g pu e yl killers. The conventional esters of 2.4-1) and cerbitel is diethylene glycol e e e y 2.4.5-T acids are generally considered to be the ether, huty1Cerbit01is diethylene ye01m0n0- best all-around systemic selective herbicides. butyl ether. et A t e C pp However, they do have one very serious shortcable for the esterification Of 2.4-D acid and coming r d awb k 2.4.5-T acid, and the resulting products are, as The shortcoming drawback just efe ed t far as the inventor has been able to ascertain, may be described by t t "biological new chemical individuals possessing unique proptility, by which is meant t tendency of t erties which render them eminently suitable for ventional esters of 2.4-1) and 2.4.5:]? acid to kill many p s At the p t time, their a or seriously injure vegetation to which they have t field f usefulness pp to b n the agrinot been applied. Conventional esters are known Cultural fieldto have exerted toxic eiiects due to biological vol- The esteiifieetion y e e d ly carried out atility at considerable distances from points of by conventional p d e a d no claim is made actual application, and for this reason the Fed-- in this application Covering e es erifiea en eral Government as well as many States have pr c sh f l w n e mp ar v but found it necessary to issue very stringent reguthe invention is not in any Way limited thereto: lations as to the use and labelling of ester formulations. Needless to state, the field of usefulness EXAMPLE I of such formulations has been greatly curtailed. Another very important object of the invention is to provide a new class of esters of 2.4 D and 2.4.5T acids, which are entirely or substantially free of the biological volatility previously re- 2.4-D acid (221 grams) is mixed with grams of butyl Carbitol, and heated gradually to -180" C. in a flask equipped with a condenser to condense the evolved water and what little butyl Carbitol is driven over by the heat.

After two hours, the esterification is practically complete and the heating may be stopped. After the resulting ester is cooled down,'the free acid EXAMPLE II "acid or 2.4.5=-T acid may be made in substantiallythe same way, using the ether corresponding to the desired end product. For instance, Carbitol, methyl Carbitol, propyl Carbitol, benzyl Carbitol, or phenyl Carbitol may be substituted in Whole or in part for the butyl Carbitol of Examples I and II.

Table of properties v Boiling Compound Specific G ravity Point figg at 1 mm.

Methyl Carbitol". 1.325 (20 C.) Carbitol 1.345 (2 C Butyl Carbitol.. 1.220 (2 C Ester of 2.4.5 1 acid:

Methyl Carbitol. 1.390 (29 C.) 29 C. Carbitolhnlleu- 1.320 (80 0.).. decomposes about 70C.

As previously stated, the esters of the invention. are substantially free of the biological volatility exhibited by the conventional esters of 2.4-D acid and 2.4.5-T acid. This can be demonstrated in several ways. For instance, two Petri dishes, one containing the butyl Carbitol ester of 2.4-D acid, and the other containing the conventional ethyl ester, are placed in the midst 'otsusceptible vegetation. After an exposure of several days, it will be seen that the vegetation surrounding the dish containing the conventional ester is dying or exhibiting marked degrees of epinasty, Whereas there is no deformation or semblance of injury in the vegetation surrounding the other dish. Another test of the same phenomenon consists in exposing a susceptible plant such as a tomato plant to each of the two types of esters under a bell jar.

Extensive experimentation has shown that the novel esters of the present inventio may be formulated with various vehicles including solubilizing agents, emulsifiers, dispersing agents,

wetting agents, stickers, etc. In the case of cerv tain emulsifiers or dispersing agents, mutual solvents or cosolvents may be used to advantage. (.ZQncentrated mixtures ot the esters with the various vehicles may be made up, and'diluted to desired concentrations with water, oil or other diluent at or prior to the time of application.

Formulations containing the esters of the invention are on an acid equivalent basis generally equal in potency and effectiveness to the conventional esters but are substantially free of the biological volatility which has greatly restricted the use of the conventional esters. As in the case of the conventional esters, the phytocidal eifect can be stepped up or intensified by the addition of oils which themselves need not be.

phytotoxic. Instead of or in addition to the oils, other substances having herbicidal activity may be incorporated in the formulation.

The following herbicidal compositions are given by way of example, the quantities being by weight: a

' KAMPLE III M H Per cent Butyl Carbitol ester of 2.lD acid 11.2 Butyl Carbitol ester of 2.4.5-T acid 23.5 Dispersing agent 6.0 Cosolvent 4.0 Heavy aromatic naphtha 55.3

EXAMPLE IV 1 I Per cent Butyl Carbitol ester of 2.4.5-T acid 47.5 Dispersing agent 10.0 Cosolvent a a 4.0 Heavy aroma-tic naphtha I 38.5

7 Per cent Methyl Carbitol ester of 2-. l-D acid 30 Dispersing agent 10- Aromatic naphtha 40 EXAMPLE v1 I Per cent Methyl Ca'rbitol ester of 2.4D acid l3 Dis'persing' agent V; 5 Qosolvent -1 5 Oil -1 7'? EXAMPLE VII 7 Per cent Methyl Carbitol ester of 2.4-D acid 15 Mahogany soap 20 cosolvent 5 Oil 60 EXAMPLE VIII V Per cent Methyl Ca'rbitol ester of 2.4-D acid Atlas C8916T (Polyethylene sorbitan esters of mixed fatty and resin acids) 10 hogany soap, which is also known as naphthenic soap, petroleum sludge soap and sulfonate naphthenate; is used in Example V. Practically any mutual. solvent or cosolvent may be used in Examples III to VII. The high molecular weight straight chain alcohols exemplified by butanol, secondary butanol, methyl amyl alcohol and 5 butyl Cellosolve have been found particularly suitable.

The formulation of Example VIII lends itself to admixture with several volumes of any oil, preferably a mineral oil such as heavy aromatic naphtha derived from petroleum or coal tar, fuel oil, and diesel oil, and subsequent emulsification in water.

The composition containing the esters of the invention may be applied to the weeds in substantially the same manner as formulations containing the conventional esters, but special precautions to prevent the killing of wanted plants in the immediate vicinity are unnecessary.

In conclusion, it is to be understood that the foregoing disclosure has been made rather detailed to comply with the patent statutes, and is not to restrict the invention beyond what is required by the state of the prior art.

I claim:

1. An ester of an acid of the group consisting of 2.4-dichlorophenoxyacetic acid and 2.4.5-tricholorophenoxyacetic acid with an ether alcohol 0f the formula R.O.CI-I2.CH2.0.CH2.CH2.0H, wherein R is of the group consisting of lower alkyl, benzyl and phenyl.

2. The ester of 2,4-dichlorophenoxyacetic acid and diethylene glycol monoethyl ether.

3. The ester of 2,4,5-trichlorophenoxyacetic acid and diethylene glycol monoethyl ether.

4. The ester of 2,4-dichlorophenoxyacetic acid and diethylene glycol monobutyl ether.

5. The ester of 2,4,5-trichlorophenoxyacetic acid and diethylene gylcol monobutyl ether.

6. The ester of 2,4-dichlorophenoxyacetic acid and diethylene glycol monophenyl ether.

WILLIAM W. ALLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,166,557 Stoesser et al July 18, 1939 2.523.187 Britton et a1. Sept. 19, 1950 2,523,189 Britton et al Sept. 19, 1950 2,523,227 Mullison Sept. 19, 1950 2,523,228 Mullison Sept. 19, 1950 

1. AN ESTER OF AN ACID OF THE GROUP CONSISTING OF 2,4-DICHLOROPHENOXYACETIC ACID AND 2.4.5-TRICHLOROPHENOXYACETIC ACID WITH AN ETHER ALCOHOL OF THE FORMULA R.O.CH2.CH2.O.CH2.CH2.OH, WHEREIN R IS OF THE GROUP CONSISTING OF LOWER ALKYL, BENZYL AND PHENYL. 